1. Field of the Invention
This invention relates to a process of packaging stacks which consist of nested cuplike objects and have the basic shape of elongate cylinders, wherein said stacks are inserted into containers to form a plurality of layers consisting each of a plurality of stacks in a horizontal attitude, and to an apparatus which is suitable for carrying out the process.
2. Description of the Prior Art
In the packaging of units which have the basic shape of elongate cylinders and must be packaged in a horizontal attitude if they cannot stand with adequate stability on their end and if they are not adequately held together in the stack to permit their manipulation by suction lifters engaging the top end of the upright stack, it is known to place such stacks by hand into containers, such as boxes, or to throw them consecutively into open-topped containers via rolling-contact chutes or transverse conveyors. In that case the bottom layer will be orderly arranged although delicate elements may be damaged or the elements of the stacks may be somewhat pulled apart so that the stacks will no longer fit between the end walls of the box. Those units which constitute the next layer will be staggered as they fall into recesses existing between adjacent units of the bottom layer. If the width of the bottom layer is an integral multiple of the diameter of the stack, free spaces will be left in the second layer on the left and right so that only the odd-numbered layers will be completely filled and the number of units in the even-numbered layers will be smaller by one. It is known to provide carton boards between the several layers so that all layers will be uniformly filled but this will complicate the packaging operation. A manual packaging is often undesired from the aspect of hygiene if the stacks consist of cups, culture disks etc. made of paper or plastic and intended for medical purposes or for a packaging of foodstuffs, such as dairy products, e.g., yoghurt, milk beverages, cream etc. . The assembling to form the stacks or endless rods may be performed on the manufacturing machine without manual action. It is desired to permit also a packaging of the stacks without a manual action. If sacklike lining wrappers made of plastic film are used for the boxes and are sealed when the boxes have been filled, a manual packaging was previously required so that there was a risk of contamination.
A fully automatic packaging in boxes which are not provided with sacklike lining wrappers can be performed by means of a known packaging machine in which a lifting deck is disposed at the end of a feed track on which individual stacks are moved and optionally roll in a transverse orientation. A box is so attached to the lifting table that the opening of the box faces the feed track, i.e., in a lateral direction. By means of a feed conveyor the stacks are successively pushed into the box from the side. When a layer has been filled, the box is lowered by the lifting deck to the extent of the height of one layer so that the next layer can be formed on said layer and on the box side wall which lies on the deck. The pushing-in is difficult because the stacks may fall into the recesses of the preceding layer. It is also difficult to properly align the individual stacks. When the box has been filled it must be tilted through 90.degree. to rest on its bottom. Separate means must be provided to prevent the stacks from being shifted and from falling out of the box during the tilting operation.